1. Field
This disclosure relates generally to semiconductor devices, and more specifically, to semiconductor device packages with heat spreaders.
2. Related Art
Some types of packaged semiconductor devices include an integrated circuit die mounted on a substrate. Wirebonds are formed between the die and the substrate to form a die assembly that connects the die to bond pads on the substrate. Mold encapsulant is formed around the die and the wirebonds to protect the die from corrosion, water, and external forces that may damage the die or break the wire bonds. A heat spreader can be positioned over the die to conduct heat away from the die during operation. An encapsulant exclusion region may be formed in the encapsulant over the die to allow the heat spreader to be attached to the top of the die with a thermally conductive interface material.
In some cases, the encapsulant exclusion region is formed during a film assisted molding process in which the package substrate and wirebonded die are placed between top and bottom molds. The molds enclose the die assembly and a pedestal is included in the mold facing the top of the die. Mold encapsulant is injected into the mold and forms around the die assembly. The pedestal prevents the encapsulant from covering the top of the die. A heat spreader can be attached to the top of the die after the die assembly is released from the mold.
In other cases, the heat spreader can include a pedestal or downset over the top of the die. The mold encapsulant can be injected between the heat spreader and the die assembly after the downset of the heat spreader is attached to the top of the die.
In either case, it is desirable to avoid void areas in the encapsulant around the die and wirebonds since moisture or other corrosive substances could enter the voids and reduce the reliability of the die assembly.